notes: send "Automatic notes merge failed" messages to stderr

All other error messages from notes use stderr.  Do the same when
alerting users of an unresolved notes merge.

Fix the output redirection in t3310 and t3320 as well.  Previously, the
tests directed output to a file, but stderr was either not captured or
not sent to the file due to the order of the redirection operators.

Signed-off-by: Todd Zullinger <tmz@pobox.com>
Acked-by: Johan Herland <johan@herland.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

builtin/notes.c

@@ -862,10 +862,10 @@ static int merge(int argc, const char **argv, const char *prefix)
 		if (create_symref("NOTES_MERGE_REF", default_notes_ref(), NULL))
 			die(_("failed to store link to current notes ref (%s)"),
 			    default_notes_ref());
-		printf(_("Automatic notes merge failed. Fix conflicts in %s and "
-			 "commit the result with 'git notes merge --commit', or "
-			 "abort the merge with 'git notes merge --abort'.\n"),
-		       git_path(NOTES_MERGE_WORKTREE));
+		fprintf(stderr, _("Automatic notes merge failed. Fix conflicts in %s "
+				  "and commit the result with 'git notes merge --commit', "
+				  "or abort the merge with 'git notes merge --abort'.\n"),
+			git_path(NOTES_MERGE_WORKTREE));
 	}
 
 	free_notes(t);

t/t3310-notes-merge-manual-resolve.sh

@@ -176,7 +176,7 @@ git rev-parse refs/notes/z > pre_merge_z
 test_expect_success 'merge z into m (== y) with default ("manual") resolver => Conflicting 3-way merge' '
 	git update-ref refs/notes/m refs/notes/y &&
 	git config core.notesRef refs/notes/m &&
-	test_must_fail git notes merge z >output &&
+	test_must_fail git notes merge z >output 2>&1 &&
 	# Output should point to where to resolve conflicts
 	test_i18ngrep "\\.git/NOTES_MERGE_WORKTREE" output &&
 	# Inspect merge conflicts
@@ -379,7 +379,7 @@ git rev-parse refs/notes/z > pre_merge_z
 test_expect_success 'redo merge of z into m (== y) with default ("manual") resolver => Conflicting 3-way merge' '
 	git update-ref refs/notes/m refs/notes/y &&
 	git config core.notesRef refs/notes/m &&
-	test_must_fail git notes merge z >output &&
+	test_must_fail git notes merge z >output 2>&1 &&
 	# Output should point to where to resolve conflicts
 	test_i18ngrep "\\.git/NOTES_MERGE_WORKTREE" output &&
 	# Inspect merge conflicts
@@ -413,7 +413,7 @@ git rev-parse refs/notes/y > pre_merge_y
 git rev-parse refs/notes/z > pre_merge_z
 
 test_expect_success 'redo merge of z into m (== y) with default ("manual") resolver => Conflicting 3-way merge' '
-	test_must_fail git notes merge z >output &&
+	test_must_fail git notes merge z >output 2>&1 &&
 	# Output should point to where to resolve conflicts
 	test_i18ngrep "\\.git/NOTES_MERGE_WORKTREE" output &&
 	# Inspect merge conflicts
@@ -494,7 +494,7 @@ cp expect_log_y expect_log_m
 
 test_expect_success 'redo merge of z into m (== y) with default ("manual") resolver => Conflicting 3-way merge' '
 	git update-ref refs/notes/m refs/notes/y &&
-	test_must_fail git notes merge z >output &&
+	test_must_fail git notes merge z >output 2>&1 &&
 	# Output should point to where to resolve conflicts
 	test_i18ngrep "\\.git/NOTES_MERGE_WORKTREE" output &&
 	# Inspect merge conflicts

t/t3320-notes-merge-worktrees.sh

@@ -61,7 +61,7 @@ test_expect_success 'merge z into x while mid-merge on y succeeds' '
 	(
 		cd worktree2 &&
 		git config core.notesRef refs/notes/x &&
-		test_must_fail git notes merge z 2>&1 >out &&
+		test_must_fail git notes merge z >out 2>&1 &&
 		test_i18ngrep "Automatic notes merge failed" out &&
 		grep -v "A notes merge into refs/notes/x is already in-progress in" out
 	) &&